The present invention relates to antenna couplers and, more particularly, to a method and construction for making an antenna coupler adapted to releasably mate with the skin of an aircraft adjacent an antenna to be tested.
A prior art approach to an antenna coupler is shown in simplified form in FIG. 1. The problem to be solved is the positioning of a test antenna 10 adjacent a working antenna 12 disposed within a housing 14 in the skin 16 of an aircraft, generally indicated as 18. The prior approach is to place the test antenna 10 within an RF shielding metal coupling enclosure, indicated by the dotted line 20, adapted to fit tightly against the skin 16 of the aircraft 18 around the housing 14. Such coupling enclosures generally work for their intended purpose but are difficult and costly to manufacture if the periphery, indicated as 22, is to tightly seal completely against the skin 16 of the aircraft 18 so as to prohibit the entry and escape of RF energy, as indicated by the arrows 24. The skin 16 of the aircraft 18 around the housing 14 is typically of a complex three-dimensional shape such that the peripheral edge 22 of the coupling enclosure 20 can only be formed for a tight fit by complex and costly manual or numerical control machining processes.
Wherefore, it is the object of the present invention to provide an antenna coupler affording complete RF shielding and sealing which is simple and economical to manufacture.